add basic menu

src/App.js

@@ -1,15 +1,17 @@
 import React from 'react';
+import MainMenu from './features/menu/Menu';
 import TimbreSwitcher from './features/timbre/timbreSwitcher';
 import './App.css';
 
 function App() {
-    return (
-        <div className="App">
-            <header className="App-header">
-                <TimbreSwitcher />
-            </header>
-        </div>
-    );
+  return (
+    <div className="App">
+      <header className="App-header">
+        <MainMenu />
+        <TimbreSwitcher />
+      </header>
+    </div>
+  );
 }
 
 export default App;